Treating urinary retention

ABSTRACT

A urethral prosthesis provides relief of urinary retention and has first and second tubular elements with an interposed bridge segment. A valve can be disposed in the second tubular element to control the flow of urine therethrough.

CROSS-REFERENCE TO RELATED APPLICATION

This incorporates by reference and claims priority to and the benefit ofU.S. provisional patent application Ser. No. 60/104,390, filed Oct. 15,1998.

TECHNICAL FIELD

The invention relates generally to urethral prostheses and methods ofinsertion into a body. More particularly, the invention relates to aurethral prosthesis having a bladder/prostate segment and a penileurethra segment connected by a bridge segment, which crosses the urinarysphincter.

BACKGROUND INFORMATION

Urinary retention in males is often caused by neurological disorders orby obstructions in the urinary tract. Neurogenic urinary retention is acondition in which a person is unable to empty his urinary bladdervoluntarily due to a neurological dysfunction of the urinary bladderand/or of the urinary sphincter. Neurogenic urinary retention is due toan inability of the bladder to contract and/or of the urinary sphincterto relax. Patients with spinal cord injuries, multiple sclerosis,Parkinson's disease, or trauma to the pelvic region may suffer fromneurogenic urinary retention on a permanent or transient basis.

Patients suffering from neurogenic urinary retention generally havelimited options for draining their bladders. These include using a Foleycatheter, intermittent catheterization, and a suprapubic drainage tube.All three options have high infection rates, are inconvenient for thepatient and/or care giver, are uncomfortable for the patient, and causethe patient emotional distress.

Urinary retention is also caused by obstructions in the urethra, such asprostatic obstructions. The prostate gland encircles the urethraimmediately below the urinary bladder. A common affliction among oldermales is benign prostatic hyperplasia (BPH), or the nonmalignantenlargement of the prostate. When the prostate becomes enlarged, it mayrestrict the urethra and thereby obstruct the flow of urine from thebladder.

A common treatment of BPH is surgical resection of the prostate andurethral tissue, but this option is not suitable for many patients. BPHafflicts primarily older males, so other health problems, such ascardiovascular disease, may prevent surgical intervention. Furthermore,potential complications associated with surgery, such as urinaryinfection, dysuria, and incontinence, may make a patient unwilling toundergo the surgery.

SUMMARY OF THE INVENTION

It is an object of the invention to relieve the symptoms of urinaryretention in males without the high infection rates and other potentialcomplications associated with current treatments. It is another objectof the invention to provide a urethral prosthesis that resides within abladder and urethra of a patient and that provides the patient controlover drainage of the bladder without the discomfort and emotionaldistress associated with conventional treatments.

In one aspect, the invention relates to a urethral prosthesis includinga first tubular element, a second tubular element, a bridge segment forjoining the first and second tubular elements, and a valve. The firsttubular element includes a distal portion with a drainage hole forreceiving urine, a proximal end and a lumen, which extends from thedrainage hole through the first tubular element to the proximal end ofthe first tubular element. At least a portion of the first tubularelement is adapted for residing in a urethra of a patient. The secondtubular element is adapted for residing in a penile urethra of apatient. The second tubular element includes a lumen extending from thebridge segment to its proximal end. The bridge segment has a diameterthat is smaller than the diameter of the first tubular element and has alumen for providing a permanent urine flow channel from the firsttubular element through the urinary sphincter. The valve is disposedwithin the lumen of the second tubular element for controlling a flow ofurine through the lumen of the second tubular element.

Embodiments according to this aspect of the invention can include thefollowing additional features. The first and second tubular elements andthe bridge segment may all be made of a pliable, biocompatible material,such as silicone rubber, for example. In another embodiment, the bridgesegment comprises a spring disposed within the pliable, biocompatiblematerial. In another embodiment, the proximal end of the second tubularelement contains a suture wire to aid in removing the prosthesis fromthe urethra of a patient. The first and second tubular elements may alsohave an external surface coated with a coating including a plurality ofgas bubbles therein.

In this aspect of the invention, the valve may be amagnetically-actuatable valve. In this embodiment, the valve includes aferromagnetic valve seat, which has an aperture for the passage of fluidtherethrough, and a valve element. The valve element includes a magnetencapsulated in a non-magnetic capsule. The capsule has a top portionand a base portion, which is wider than the top portion. The valveelement is magnetically attracted to the valve seat so that it blocksthe flow of fluid through the aperture in the valve seat.

In a second aspect, the invention relates to a urethral prosthesisincluding a first tubular element, a second tubular element, and abridge segment of suture wires connecting the first and second tubularelements. The bridge segment resides within the urinary sphincter. Thefirst tubular element has a drainage hole for receiving urine in itsdistal portion, a lumen extending from the drainage hole to its proximalend, and an external surface coated with a coating including a pluralityof gas bubbles disposed therein. The first tubular element is adaptedfor residing at least partially in the urethra of a patient. The secondtubular element is adapted for residing in a penile urethra of thepatient and has a lumen.

Embodiments according to this aspect of the invention can include thefollowing additional features. The second tubular element may also havean external surface coated with a coating including a plurality of gasbubbles. The first and second tubular elements may be composed of apliable, biocompatible material, such as silicone rubber, for example.The second tubular element may include a suture wire attached to itsproximal end to aid in removing the prosthesis from the patient.Finally, the second tubular element may include an optical lens embeddedin its wall.

In a third aspect, the invention relates to a urethral prosthesisincluding a first tubular element, a second tubular element, and abridge segment of suture wires connecting the first and second tubularelements. The bridge segment resides within the urinary sphincter. Thefirst tubular element has a drainage hole for receiving urine in itsdistal portion, and a lumen extending from the drainage hole to itsproximal end. The first tubular element is adapted for residing at leastpartially in the urethra of a patient. The second tubular element isadapted for residing in a penile urethra of the patient and has a lumenand includes an optical lens embedded in its wall.

Embodiments according to this aspect of the invention can include thefollowing additional features. The first and second tubular element mayalso have an external surface coated with a coating including aplurality of gas bubbles. The first and second tubular elements may becomposed of a pliable, biocompatible material, such as silicone rubber,for example. The second tubular element may include a suture wireattached to its proximal end to aid in removing the prosthesis from thepatient.

The invention also relates to systems and methods for treating urinaryretention. A system of the invention includes a urethral prosthesis ofany of the above-described embodiments, an inflation cannula, and aninflatable balloon. The inflation cannula includes a lumen, which is incommunication with the inflatable balloon for passage of fluid or gas tothe balloon, so as to inflate the balloon. In one embodiment, theballoon covers at least a portion of the first tubular element wheninflated. In another embodiment, the balloon covers the second tubularelement when inflated.

A method of using such a system in which the balloon covers at least aportion of the first tubular element includes inserting the prosthesisin a urethra of a patient, pushing the prosthesis within the urethra sothat the drainage hole is positioned in a bladder of the patient,delivering a volume of fluid or gas to the balloon through the inflationcannula so as to inflate the balloon, and withdrawing the prosthesisuntil a resistance is felt. This resistance indicates that the bridgesegment of the prosthesis is positioned within the urinary sphincter.

A method of using such a system in which the balloon covers the secondtubular element includes inserting the prosthesis in a urethra of apatient, pushing the prosthesis within the urethra until a firstresistance is felt, delivering a volume of fluid or gas to the balloonthrough the inflation cannula so as to inflate the balloon, and pushingthe prosthesis farther into the urethra until a second resistance isfelt. This second resistance indicates that the bridge segment of theprosthesis is positioned within the urinary sphincter of the patient.

In an alternative embodiment of the method, the first and/or secondtubular elements have an external surface coated with a coatingincluding a plurality of gas bubbles. The method then further includesimaging the first and/or second tubular elements by ultrasound.

In alternative embodiments of the systems described above, a transduceris disposed within the balloon. A method of using such a system in whichthe balloon covers at least a portion of the first tubular elementincludes the steps of inserting the prosthesis in a urethra of apatient, pushing the prosthesis within the urethra so that the drainagehole is positioned in a bladder of the patient, delivering a volume offluid or gas to the balloon through the inflation cannula so as toinflate the balloon, and withdrawing the prosthesis until a markedincrease occurs in the pressure. This marked increase in pressureindicates that the bridge segment of the prosthesis is positioned withinthe urinary sphincter.

A method using such a system in which the balloon covers the secondtubular element includes the steps of inserting the prosthesis within aurethra of a patient, pushing the prosthesis within the urethra until afirst resistance is felt, delivering a volume of fluid to the balloonvia the inflation cannula, monitoring a pressure of the balloon via thetransducer, and pushing the prosthesis farther into the urethra until amarked increase occurs in the pressure. This marked increase indicatesthat the bridge segment is positioned within the urinary sphincter.

Methods of inserting a urethral prosthesis using such a system includeinserting the urethral prosthesis into a urethra of the patient, pushingthe prosthesis within the urethra until a first resistance is felt,delivering a volume of fluid via the inflation cannula to the inflatableballoon, so as to inflate the balloon, and pushing until a secondresistance is felt. In an alternative embodiment, pressure in theballoon is monitored via a transducer, which is disposed within theballoon.

In an alternative embodiment of the above method, the first and/orsecond tubular elements have an external surface coated with a coatingincluding a plurality of gas bubbles. The method then further includesimaging the first and/or second tubular elements by ultrasound. In anadditional alternative embodiment, a transducer is inserted within thelumen of the second tubular element of the prosthesis for imaging theprosthesis by ultrasound and confirming that the bridge segment isproperly positioned so that it spans the urinary sphincter. Theultrasound transducer may also be advanced into the lumen of the firsttubular element after passing through the bridge segment, so as toconfirm placement of the drainage hole in the bladder.

Another method of inserting a urethral prosthesis includes inserting aurethral prosthesis of any of the above-described embodiments into aurethra of a patient until the drainage hole of the first tubularelement resides in the bladder and withdrawing the prosthesis until aresistance is felt. Embodiments of this method can include the followingadditional features. The external surface of the first and/or secondtubular elements include an external surface coated with a coatingincluding a plurality of gas bubbles. The method then further includesimaging the first and/or second tubular elements by ultrasound. In anadditional alternative embodiment, a transducer is inserted within thelumen of the second tubular element of the prosthesis for imaging theprosthesis by ultrasound and confirming that the bridge segment isproperly positioned so that it spans the urinary sphincter. Theultrasound transducer may also be advanced into the lumen of the firsttubular element after passing through the bridge segment, so as toconfirm placement of the drainage hole in the bladder.

Another method of inserting a urethral prosthesis includes inserting aurethral prosthesis of any of the above-described embodiments into aurethra of a patient and viewing the bridge segment of the prosthesiswith an optical lens, so as to position the bridge segment within theurinary sphincter of the patient. In an alternative embodiment, themethod also includes irrigating the urethra.

In other alternative embodiments of the method, the optical lens is anendoscope. The endoscope can be adapted for sliding within an externalgroove of the second tubular element. Also, the optical lens may beadapted for passing through the lumen of the second tubular element.Alternatively, the optical lens may be embedded within a wall of thesecond tubular element. Finally, the external surface of the firstand/or second tubular elements include an external surface coated with acoating including a plurality of gas bubbles. The method then furtherincludes imaging the first and/or second tubular elements by ultrasound.In an additional alternative embodiment, a transducer is inserted withinthe lumen of the second tubular element of the prosthesis for imagingthe prosthesis by ultrasound and confirming that the bridge segment isproperly positioned so that it spans the urinary sphincter. Theultrasound transducer may also be advanced into the lumen of the firsttubular element after passing through the bridge segment, so as toconfirm placement of the drainage hole in the bladder.

The foregoing and other objects, aspects, features, and advantages ofthe invention will become more apparent from the following descriptionand from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention.

FIG. 1 is an illustration of an embodiment of a urethral prosthesis ofthe invention for use in treating neurogenic urinary retention.

FIG. 2 shows the urethral prosthesis of FIG. 1 residing in a urethra ofa patient.

FIG. 3A is an illustration of a valve for use in a urethral prosthesisof the invention in its closed state.

FIG. 3B is an illustration of a valve for use in a urethral prosthesisof the invention in its open state.

FIG. 4 is an illustration of an embodiment of a urethral prosthesis ofthe invention for use in treating urinary retention due to obstructionsin the urethra.

FIG. 5 shows a urethral prosthesis of FIG. 4 residing in a urethra of apatient.

FIG. 6 is a cross-sectional view of a second tubular element of aprosthesis of the invention containing an optical lens embedded in itswall.

FIG. 7 is an illustration of a configuration for use in inserting aurethral prosthesis of the invention.

FIG. 8A is an illustration of a configuration for inserting a urethralprosthesis of the invention using an inflatable balloon that covers thesecond tubular element.

FIG. 8B is an illustration of the configuration of FIG. 8A in which theballoon is inflated.

FIG. 8C is an illustration of a positioning stylet for use in methods ofthe invention.

FIGS. 9A-9D are illustrations of a method of inserting a urethralprosthesis of the invention using a system of FIGS. 8A-8C.

FIG. 10A is an illustration of a configuration for inserting a urethralprosthesis of the invention using an inflatable balloon that covers atleast a portion of the first tubular element.

FIG. 10B is an illustration of the configuration of FIG. 10A in whichthe balloon is inflated.

FIGS. 11A-11C are illustrations of a method of inserting a urethralprosthesis of the invention using a system of FIGS. 10A-10B.

FIG. 12 is an illustration of a system for use in inserting a urethralprosthesis of the invention using a transducer to monitor changes inpressure of the balloon.

FIG. 13A is an illustration of a configuration for inserting a urethralprosthesis of the invention using an endoscope.

FIG. 13B is a cross-sectional view, taken along line 13B-13B in FIG.13A, of the urethral prosthesis which has an external groove foraccommodating the endoscope.

FIG. 14 is an illustration of a positioning stylet having fluid deliveryports.

FIG. 15A is a cross-sectional view of a second tubular element of aurethral prosthesis of the invention having an optical lens embedded inits wall and a positioning stylet positioned within its lumen, such asthe stylet of FIG. 14.

FIG. 15B is a cross-sectional view of a second tubular element of aurethral prosthesis of the invention having an endoscope and apositioning stylet positioned within its lumen.

DESCRIPTION

The invention relates to a urethral prosthesis for providing relief ofurinary retention. A urethral prosthesis of the invention includes firstand second tubular elements with an interposed bridge segment. The firstand second tubular elements both have lumens extending therethrough. Thebridge segment can be a generally non-compressible section with adiameter smaller than the diameter of each of the first and secondtubular elements. Alternatively, the bridge segment can comprise atleast one suture extending between the two tubular elements. A valve canbe disposed in the lumen of the second tubular element, so as to controlthe flow of urine through the second tubular element.

When inserted into a patient, a drainage hole in the first tubularelement resides within or near the patient's bladder, the remainder ofthe first tubular element resides within the prostatic urethra, thebridge segment passes through the urinary sphincter, and the secondtubular element resides within the penile urethra. A urethral prosthesisof the invention therefore provides a channel for the flow of urine fromthe bladder out of the patient's body.

Systems and methods are also provided for the treatment of urinaryretention using a urethral prosthesis, such as the types of prosthesesdescribed above. A system and method of the invention provides for theuse of an inflatable balloon to locate the urinary sphincter and therebyensure proper positioning of the urethral prosthesis of the invention.Other methods ensure proper positioning by detecting resistance or byviewing the urinary sphincter with an optical lens during insertion.

An embodiment of a urethral prosthesis of the invention for use intreatment of neurogenic urinary retention is illustrated in FIG. 1. Theprosthesis 9 includes a first tubular element 10, a bridge segment 12,and a second tubular element 14. The first tubular element 10 and thesecond tubular element 14 may be composed of any pliable biocompatiblematerial, such as silicone rubber, for example. In one embodiment, thefirst tubular element 10 and the second tubular element 14 each has alumen that is circular in cross-sectional shape. In an alternativeembodiment, the lumen of the first tubular element 10 and the lumen ofthe second tubular element 14 are not circular in cross-sectional shapeand may comprise a C-shape or a semi-circular shape, for example. Theexternal surfaces of the first tubular element 10 and the second tubular14 may be modified accordingly in order to create the non-circularshapes.

In some embodiments, the external surfaces of both the first tubularelement 10 and the second tubular element 14 are coated with a plasticcoating, such as a silicone coating, which is impregnated with gasbubbles. This coating makes the prosthesis echogenic, so that ultrasoundmay be used to ensure proper positioning of the prosthesis duringinsertion or to confirm proper placement of the prosthesis after it isinserted.

The first tubular element 10 and the second tubular element 14 both havelumens and are open at their proximal ends. The second tubular element14 is also open at its distal end. The distal end of the first tubularelement 10 is closed, but a drainage hole 16 is provided near the distalend. The bridge segment 12 has a reduced diameter as compared to thefirst tubular element 10 and the second tubular element 14. Disposedwithin the bridge segment 12 is a spring 18. The second tubular element14 includes a valve 20 and suture wires 22. These suture wires 22 aid inremoval of the prosthesis from the urethra of the patient. Theprosthesis may be removed by pulling on suture wires 22. The suturewires 22 can be made of thin strands of a polymeric material, ofsilicone, metal, plastic, or rubber. The suture wires 22 may also bebraided or monofilaments.

The separate sections of the urethral prosthesis 9 shown in FIG. 1 areadapted for positioning within different segments of the urethra and thebladder. FIG. 2 is an illustration of the urethral prosthesis 9 in aurethra of a patient. The first tubular element 10 is inserted so thatthe drainage hole 16 resides within the bladder 24 of the patient. Theremainder of the first tubular element 10 spans the prostatic urethra,which is identified as that portion of the urethra surrounded by theprostate 26. The bridge segment 12 spans the urinary sphincter 28, so asto provide a permanently open channel through which urine from thebladder can flow into the second tubular element 14, which resides inthe penile urethra 30.

In one embodiment, the bridge segment 12 is non-compressible so as tohold the urinary sphincter in an open position and thereby provide apermanently open channel for the flow of urine from the bladder 24. Thebridge segment 12 may be composed of any pliable biocompatible material,such as silicone rubber, for example. Patients suffering from neurogenicurinary retention are unable to control the opening and closing of theurinary sphincter and/or are unable to contract the bladder. Byproviding an open channel for the flow of urine across the urinarysphincter, these problems are alleviated. Furthermore, the bridgesegment 12 includes the spring 18, which imparts flexibility to thebridge segment 12, thereby increasing the comfort level of the patient.The suture wires 22 extend into the penile urethra 30, where they may begrasped and pulled in order to remove the prosthesis 9 from the urethraof the patient.

To control the flow of urine through the second tubular element 14 andout of the body, a valve 20 is disposed within the second tubularelement 14. A suitable valve for use in a urethral prosthesis, asdescribed above, is as described in U.S. Pat. No. 5,366,506, the entiredisclosure of which is hereby incorporated by reference herein. In oneembodiment, as shown in FIG. 3A, a valve includes a ferromagnetic valveseat 32, which includes apertures 34 and 34′. The valve 20 also includesa valve element 38, which includes a magnet 36. The walls of the valveelement 38 are non-magnetic. As shown in FIG. 3A, the bottom portion ofthe valve element 38 is wider than the top portion of the valve element38. Absent any external force, the valve element 38 is magneticallyattracted to the valve seat 32, thereby blocking the aperture 34. Thevalve 20 is therefore in its closed position and fluid cannot flowthrough it. When an external magnetic force is applied to the valve 20,such as by contacting an exterior of a penis in which such a valveresides with a magnet, the valve element 38 is displaced so as to openthe aperture 34, as is shown in FIG. 3B. In the open position, fluidflows into the valve 20 through the aperture 34′ and then through theaperture 34 to the remainder of the penile urethra 30, and then out ofthe body.

An embodiment of a urethral prosthesis 39 of the invention for use intreating urinary retention due to an obstruction in the urethra is shownin FIG. 4. In this embodiment, the first tubular element 10 and thesecond tubular element 14 are as described above. The first tubularelement 10 has a closed distal end, except for a drainage hole 16. Inthis embodiment of the invention, the bridge segment 12 includes suturewires 40.

In the case of urinary retention due to an obstruction in the urethra,patients have the ability to control their urinary sphincters andbladder contractions. A bridge segment that maintains a permanent flowchannel is therefore not required. This embodiment of the inventiontherefore allows the patient to control the urinary sphincter, while theprosthesis otherwise maintains an open channel in the urethra. Anillustration of a prosthesis 39 in a patient is shown in FIG. 5.Obstructions of the urethra commonly occur when the prostate 26 becomesenlarged and restricts the prostatic urethra, thereby blocking it. Ascan be seen in FIG. 5, the first tubular element 10 resides with itsdrainage hole 16 in the bladder 24, and with the remainder of the firsttubular element 10 spanning the prostatic urethra. The first tubularelement 10 therefore serves to maintain an open channel for the flow ofurine through the prostatic urethra. When the urinary sphincter 28 isclosed, the suture wires 40 are compressed. When the urinary sphincter28 is open, urine flows into the second tubular element 14 and throughthe penile urethra 30 to the exterior of the body.

In one embodiment of the urethral prosthesis 39, as shown in FIG. 4, thefirst tubular element 10 and the second tubular element 14 are composedof a pliable, biocompatible material, such as silicone rubber. Inanother embodiment, the first tubular element 10 and the second tubularelement 14 have external surfaces coated with a plastic coatingincluding a plurality of gas bubbles. As described above, this echogeniccoating provides for ultrasound imaging of the device during or afterinsertion. The prosthesis 39 also contains suture wires 22, which aid inremoving the prosthesis 39 from the patient, also as described above.

In an alternative embodiment of a urethral prosthesis for relievingurinary retention due to obstructions in the urethra, an optical lens isembedded within the wall of the second tubular element 14. FIG. 6 showsa cross-sectional view of a second tubular element 14 having an opticallens 42 embedded within its wall. The optical lens 42 may be used toensure proper placement of the prosthesis during insertion. In oneembodiment, the optical lens 42 is disposed at the distal end of thesecond tubular element 14, so that the urinary sphincter 28 may beviewed during the insertion procedure. (This insertion procedure isdescribed in more detail below.) The first and second tubular elementsof a urethral prosthesis containing an optical lens embedded within thewall of the second tubular element may or may not have external surfacescoated with an echogenic coating, as described above.

Methods of the invention relate to the insertion of a urethralprosthesis in a urethra and bladder of a patient. Methods the inventionmay include the use of any of the urethral prostheses described above.One such configuration for inserting a urethral prosthesis is shown inFIG. 7. The configuration in FIG. 7 includes the urethral prosthesis 9,the insertion sleeve 44, and the retractor 46. The insertion sleeve 44is disposed over the second tubular element 14 and the bridge segment12, and is partially disposed over the first tubular element 10. Theretractor 46 is releasably attached to the proximal end of the secondtubular element 14. The configuration of FIG. 7 is shown with theprosthesis 9 by way of example only. The kit may also be used inconjunction with the prosthesis 39, or any of the above-describedembodiments of prostheses 9 and 39.

A method of insertion of a urethral prosthesis involves inserting theprosthesis 9, the insertion sleeve 44, and the retractor 46 into aurethra of a patient. The distal end of the first tubular element 10 isinserted first. The prosthesis 9 is inserted so that the drainage hole16 resides in the bladder 24 of the patient, as shown in FIG. 2. If thefirst tubular element has an echogenic coating, the first tubularelement 10 with the drainage hole 16 in the bladder 24 may be imagedwith ultrasound, as described above. Alternatively, the placement of theprosthesis 9 may be imaged by inserting an ultrasound transducer intothe lumen of the second tubular element 14. The ultrasound transducermay also be advanced through the bridge segment 12 of the prosthesis 9and into the lumen of the first tubular element 10, so as to view theplacement of the first tubular element within the bladder 24. Theinsertion sleeve 44 is then removed, and the retractor 46 is used topull the prosthesis 9 back toward the opening of the urethra until aresistance is felt by the user. This resistance indicates that thebridge segment 12 is properly positioned in the urinary sphincter 28, asshown in FIG. 2. The retractor 46 is then disengaged from the secondtubular element 14 and removed from the urethra. Proper positioning ofthe prosthesis may be confirmed with urethroscopy or ultrasound asdescribed above.

A system of the invention is shown in FIGS. 8A-8C. The system containsthe prosthesis 39, a pusher 48, a positioning stylet 50, an inflationcannula 52, and an inflatable balloon 54. The pusher 48 is sized andshaped for butting up against the proximal end of the second tubularelement 14, so that it pushes against the second tubular element 14 andthereby advances the prosthesis 39 into a urethra of a patient. Thepusher 48 has a lumen for insertion of the positioning stylet 50therein. An illustration of the positioning stylet 50 is shown in FIG.8C. The positioning stylet 50 is adapted to reside within the lumens ofthe pusher 48, the second tubular element 14, and the first tubularelement 10, so as to maintain the prosthesis 39 in its extended positionduring the insertion procedure. Without the stylet 50, suture wires 40may become bent, twisted, or collapsed during insertion.

The inflation cannula 52 of FIG. 8A also has a lumen, which is incommunication with the inflatable balloon 54. To inflate the balloon 54,fluid or gas is delivered through the lumen of the inflation cannula 52.The balloon 54 is disposed over the second tubular element 14. In FIG.8A, the balloon 54 is not inflated. FIG. 8B is an illustration of thesystem in which the balloon 54 is inflated over the second tubularelement 14. The balloon 54 may be compliant or non-compliant. Balloonsare standardized so that the injection of a known amount of fluid withinthe balloon induces inflation of the balloon to a specific diameter.Balloons may also be standardized with respect to diameter and pressure.Once the system of FIGS. 8A-8C is closed, a relation exists between thepressure within the system and the diameter of the balloon. The systemis shown with the prosthesis 39 by way of example only. The system mayalso be used in conjunction with the prosthesis 9, or any of theabove-described embodiments of prostheses 9 and 39.

A method for inserting a prosthesis using the system shown in FIGS.8A-8C is shown in FIGS. 9A-9D. In this method, the prosthesis 39, thepositioning stylet 50, the pusher 48, the inflation cannula 52, and theballoon 54 are inserted into a urethra of a patient, with the distal endof the first tubular element 10 being inserted first. The prosthesis 39is pushed by the pusher 48, along with the positioning stylet 50, untila first resistance is felt. This first resistance indicates that thedistal end of the first tubular element 10 has contacted the urinarysphincter 28, as shown in FIG. 9A. The balloon 54 is then inflated bydelivering fluid or gas via the inflation cannula 52 to the interior ofthe balloon 54. The balloon 54 inflates over the second tubular element14, as shown in FIG. 9B. The prosthesis 39 is then pushed farther intothe urethra until a second resistance is felt. This second resistanceindicates that the balloon 54 has contacted the urinary sphincter 28, asshown in FIG. 9C. The pusher 48 and the inflation cannula 52 are removedfrom the urethra so as to deflate the balloon 54. At this point, theprosthesis 39 is properly positioned within the urethra of the patient,such that the drainage hole 16 is residing in the bladder 24 and thebridge segment 12 spans the urinary sphincter 28, as shown in FIG. 9D.Proper placement of the prosthesis may be confirmed by urethroscopy orultrasound, as described above.

An alternative system of the invention is shown in FIGS. 10A-10B. Thesystem shown in FIG. 10A contains the prosthesis 39, a pusher 48, aninflation cannula 49, and an inflatable balloon 51. The pusher 48 issized and shaped for butting up against the proximal end of the secondtubular element 14, so that it pushes against the second tubular element14 and thereby advances the prosthesis 39 into a urethra of a patient.The pusher 48 has a lumen for insertion of the inflation cannula 49therein. The inflation cannula is adapted to reside within the lumens ofthe pusher 48, the second tubular element 14, and the first tubularelement 10. The inflation cannula 49 also has a lumen, which is incommunication with the inflatable balloon 51 so as to deliver a volumeof fluid or gas to the balloon 51 and thereby inflate the balloon 51. Asshown in FIG. 10B, the balloon 51 covers at least a portion of the firsttubular element 10 when it is inflated. The balloon 51 is inflated at aposition on the first tubular element 10 that resides in the bladder ofa patient just above the prostate gland when inserted.

A method for inserting a prosthesis using the system shown in FIGS.10A-10B is shown in FIGS. 11A-11C. In this method, the prosthesis 39 thepusher 48, the inflation cannula 49, and the balloon 51 are insertedinto a urethra of a patient, with the distal end of the first tubularelement 10 being inserted first, as shown in FIG. 11A. The prosthesis ispushed by the pusher 48, along with the inflation cannula 49, until thedrainage hole 16 of the first tubular element 10 is positioned withinthe bladder 24, as shown in FIG. 11B. The balloon 51 is then inflated bydelivering a volume of fluid or gas via the inflation cannula 49 to theinterior of the balloon 51. The balloon 51 inflates over at least aportion of the first tubular element 10, as shown in FIG. 1 IC. Theprosthesis 39 is then withdrawn (such as, for example, by using aretractor, as in FIG. 7) until a resistance is felt. This resistanceindicates that the balloon 51 is contacting the opening 53 of thebladder 24 just above the prostate 26. This indicates that theprosthesis is properly positioned so that the bridge segment 12 spansthe urinary sphincter 28. Proper placement of the prosthesis may beconfirmed by urethroscopy or ultrasound, as described above.

In an alternative embodiment of the system of FIGS. 8A-8C, as shown inFIG. 12, a transducer (not shown) is disposed within the balloon 54. Thelocation of the transducer within the closed system is unimportant aslong as it is located within and senses changes in pressure within thearea containing the fluid or gas. The transducer is in electricalcommunication via the connecting wire 51 with the controller 53. Thecontroller 53 monitors variations in pressure. The controller 53includes an indicator 55, which displays a plot 59 of the changes inpressure as a function of time or as a function of distance of insertioninto the urethra. Indicator 55 may be a video monitor or a print-outdisplay, for example. A marked increase in pressure 57, indicates thatthe balloon 54 has contacted the urinary sphincter 28. Detection of thelocation of the urinary sphincter 28 is then made by a visual reading ofthe plot 59, so as to ensure accurate placement of the prosthesis 39.Alternatively, when the balloon used is a compliant balloon, the plot 59may be standardized to yield a defined pressure for a specific diameterfor a known volume of inflation fluid. Alternatively, the embodiment ofthe system shown in FIGS. 10A-10B may be similarly adapted. For example,a transducer may be disposed within balloon 51 and may indicateplacement of the prosthesis 39 by detecting marked increases in pressureas the prosthesis 39 is withdrawn from the urethra.

In an alternative embodiment, the system shown in FIG. 12 is used tomeasure the competency of the sphincter or detrusor muscles. This isaccomplished by passing the balloon 54 with a known freestandingpressure-volume curve into the desired location and incrementallyinflating it with known volumes of fluid. After each inflation of theballoon 54, a pressure measurement is taken and a pressure volume curvegenerated. By calculating the area difference between the curves, thenet amount of work done by the sphincter is obtained.

In another alternative embodiment, the system of FIG. 12 is used todetermine adequate bulking pressures or volumes used during bulkingprocedures to remediate sphincter incontinence, for example. The systemmay be used to monitor the injection of agents typically used to bulksphincters and create constrictions, such as to treat stressincontinence (AUS, Collagen products) or GERD. By placing a balloon 54with the transducer in the desired position to be bulked, one can thenmonitor the compliance of the restriction created with the agent as itis injected. Clinical outcomes can be correlated to the compliancemeasured with this device to determine how much bulking agent is neededfor the desired outcome.

The system of FIG. 12 may also have applications in urodynamicmeasurements, such as, compliance of body tissues within the urinarytract, arterial stenosis, aneurysm detection, or other areas wherestricture, enlargement, or body tissue compliance quantification ispertinent.

Another configuration for insertion of a urethral prosthesis is shown inFIGS. 13A-13B. This configuration includes the prosthesis 39, the pusher48, the positioning stylet 50, and an endoscope 56. The positioningstylet 50 has a lumen and contains fluid delivery ports 58, which arepositioned to deliver fluid through the bridge segment 12 during theinsertion procedure. Irrigating the insertion site during the insertionprocedure is necessary to keep the optical lens 42 of the endoscope 56clear for viewing. The positioning stylet 50 with delivery ports 58 isillustrated in FIG. 14.

In the configuration of FIGS. 13A-13B, the second tubular element 14 andthe pusher 48 both have external grooves to allow the endoscope 56 toslide along the external surface of both the second tubular element 14and the pusher 48. A cross-sectional view of the second tubular element14 having an external groove is shown in FIG. 13B. As shown in FIG. 13B,the endoscope 56 fits within the external groove of the second tubularelement 14. Also shown in the lumen of the second tubular element 14 isthe positioning stylet 50. The configuration is shown with theprosthesis 39 by way of example only. The configuration may also be usedin conjunction with the prosthesis 9, or any of the above-describedembodiments of prostheses 9 and 39.

In alternative embodiments of this configuration, the optical lens 42 isembedded within the wall of the second tubular element 14, as shown inFIG. 15A. FIG. 15A is a cross-sectional view of the second tubularelement 14. In this embodiment, the second tubular element 14 and thepusher 48 do not have external grooves. Also shown in FIG. 15A is thepositioning stylet 50 within the lumen of the second tubular element 14.In another alternative embodiment, both the endoscope 56 and thepositioning stylet 50 are adapted to fit within the lumen of the secondtubular element 14, as shown in FIG. 15B.

A method of inserting a urethral prosthesis 39 using such aconfiguration include inserting the prosthesis 39, the pusher 48, thepositioning stylet 50, and the endoscope 56 into a urethra of a patient.The distal end of the first tubular element 10 is inserted first, andthe prosthesis 39 is advanced farther into the urethra by pushingagainst the proximal end of the second tubular element 14 with thepusher 48 and by pushing with the positioning stylet 50. While pushingthe prosthesis 39 into the urethra, the endoscope 56 is used to view thebridge segment 12. In one embodiment, the urethra is irrigated bydelivering a fluid through the lumen of the positioning stylet 50 andthrough the fluid delivery ports 58. The fluid may be any biologicalcompatible fluid, such as saline, for example.

In this method of insertion, the bridge segment 12 is viewed with theendoscope 56 to determine when the bridge segment 12 is positioned suchthat it spans the urinary sphincter 28, as shown in FIG. 5. Thepositioning stylet 50, the pusher 48, and the endoscope 56 are thenremoved from the urethra. If the second tubular element 14 includes theoptical lens 42 embedded within its wall, the method does not requireuse of the endoscope 56 for viewing. The bridge segment 12 is viewedwith the embedded optical lens 42. Proper placement of the prosthesismay be confirmed by urethroscopy or ultrasound, as described above.

The above described systems and methods provide the patient control overthe draining of the bladder. Urethral prostheses of the invention mayalso be used in situations where it is not desirable or possible for thepatient to have control over the draining of the bladder. In suchcircumstances, the distal end of the first tubular element of theprosthesis may be open, and a catheter, such as a Foley catheter, forexample, may be inserted through the lumens of the second tubularelement, bridge segment, and first tubular element of the prosthesis.The catheter can then be attached to a urine collection bag and meter.This embodiment allows for the monitoring of urine production by thepatient.

Variations, modifications, and other implementations of what isdescribed herein will occur to those of ordinary skill in the artwithout departing from the spirit and the scope of the invention asclaimed. Accordingly, the invention is to be defined not by thepreceding illustrative description but instead by the spirit and scopeof the following claims.

1-95. (canceled)
 96. A urethral prosthesis, comprising: a tubularelement including a distal portion and a closed distal end, the distalportion defining a drainage hole for receiving urine from a bladder of apatient, the tubular element further including a proximal end and alumen extending from the drainage hole through the tubular element tothe proximal end, the tubular element further including an inflationballoon, the tubular element configured to maintain an open channel forfluid flow through a prostatic urethra of the patient when theprosthesis is positioned within the patient; and an element coupled tothe tubular element, the element including a spring member disposedwithin a pliable material.
 97. The urethral prosthesis of claim 96,wherein the element is coupled directly to the tubular element.
 98. Theurethral prosthesis of claim 96, wherein the element extends proximallyfrom the tubular element.
 99. The urethral prosthesis of claim 96,wherein the inflation balloon is disposed near the drainage hole. 100.The urethral prosthesis of claim 96, wherein the inflation balloon isdisposed on the tubular element.
 101. The urethral prosthesis of claim96, wherein the inflation balloon is inflatable over at least a portionof the tubular element.
 102. The urethral prosthesis of claim 96,wherein the tubular element comprises a pliable, biocompatible material.103. The urethral prosthesis of claim 96, wherein the tubular elementincludes a silicone coating.
 104. The urethral prosthesis of claim 96,wherein the tubular element comprises silicone rubber.
 105. The urethralprosthesis of claim 96, further comprising at least one removal suture.106. The urethral prosthesis of claim 105, wherein the at least oneremoval suture is connected to the tubular element.
 107. The urethralprosthesis of claim 105, wherein the at least one removal suture isconnected to the element.
 108. A urethral prosthesis, comprising: (a) atubular element including a distal portion and a closed distal end, thedistal portion defining a drainage hole for receiving urine from abladder of a patient, the tubular element further including a proximalend and a lumen extending from the drainage hole through the tubularelement to the proximal end, the tubular element further including alength defined between the proximal end and the distal end, the tubularelement configured to maintain an open channel for fluid flow through aprostatic urethra of the patient when the prosthesis is positionedwithin the patient; (b) an inflation balloon disposed on the tubularelement; (c) at least one suture extending from the proximal end of thetubular element, the at least one suture passing through a urinarysphincter of the patient when the prosthesis is positioned within thepatient to allow the patient to control the urinary sphincter; and (d) anon-inflatable element extending from a proximal end of the at least onesuture, the non-inflatable element including a proximal end and a distalend and defining a length between the proximal end and the distal end,the length of the tubular element being greater than the length of thenon-inflatable element.
 109. The urethral prosthesis of claim 108,wherein the distal end of the non-inflatable element has an outerdiameter greater than an outer diameter of the proximal end of theelement.
 110. The urethral prosthesis of claim 108, wherein thenon-inflatable element is configured to be disposed within a penileurethra.
 111. The urethral prosthesis of claim 108, wherein thenon-inflatable element has a width and is configured to substantiallymaintain the width during both insertion and while maintained within aurethra.
 112. The urethral prosthesis of claim 108, further comprisingat least one removal suture coupled to at least one of thenon-inflatable element or the tubular element.
 113. The urethralprosthesis of claim 108, wherein the inflation balloon is disposed nearthe drainage hole.
 114. The urethral prosthesis of claim 108, whereinthe tubular element comprises a pliable, biocompatible material. 115.The urethral prosthesis of claim 108, wherein the tubular elementcomprises silicone rubber.